Tread portion of an automobile tire



FIG. 1 is a front view of a tread portion of an automobile tire;

FIG. 2 is a perspective view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a fragmentary enlarged view showing the details of the tread portion thereof; and,

FIG. 5 is an end view taken along line 5-5 in FIG. 4.

Broken lines are used to show portions of the tire and tread not being claimed, and thus form no part of the claimed design. 

The ornamental design for a tread portion of an automobile tire, as shown and described. 